Medical device suitable for treating reflux from a stomach to an oesophagus

ABSTRACT

A medical treatment device ( 200 ), for treating reflux from a stomach ( 201 ) to an oesophagus ( 202 ) and for delivering a therapeutic agent to an inner surface of the oesophagus ( 202 ), comprises a valve member ( 203 ), a lining member ( 204 ), and a support member ( 205 ). The valve member ( 203 ) is movable between a closed configuration and an open configuration, in which the valve member ( 203 ) facilitates passage of material between the oesophagus ( 202 ) and the stomach ( 201 ). The valve member ( 203 ) is biased towards the closed configuration and gradually moves over a period of 4 to 10 secs from the open configuration to the closed configuration. The support member ( 205 ) supports the device ( 200 ) relative to the oesophagus ( 202 ) and the stomach ( 201 ). The lining member ( 204 ) lines part of the inner surface of the oesophagus ( 202 ) for delivery of a therapeutic agent to the oesophagus ( 202 ).

INTRODUCTION

This invention relates to a medical device suitable for treating refluxfrom a stomach to an oesophagus, to a medical device suitable fordelivering a therapeutic agent to an alimentary canal, to a method ofdelivering a medical treatment device to a treatment location in analimentary canal, and to a delivery system for delivering a medicaltreatment device to a treatment location in an alimentary canal.

STATEMENTS OF INVENTION

According to the invention there is provided a medical device suitablefor treating reflux from a stomach to an oesophagus, the devicecomprising:—

-   -   a valve member;    -   the valve member being movable between an open configuration to        facilitate passage of material between an oesophagus and a        stomach, and a closed configuration;    -   the valve member being configured to gradually move from the        open configuration to the closed configuration over a        predetermined period of time.

In the closed configuration the valve member fully prevents orsubstantially minimises any reflux from the stomach to the oesophagus.

The valve member moves gradually from the open configuration to theclosed configuration. The valve member thus acts in a similar manner tothe natural physiological action of the oesophageal sphincter.

In one embodiment of the invention in the open configuration the valvemember is configured to facilitate passage of material from anoesophagus into a stomach. In the open configuration the valve membermay be configured to facilitate passage of material from a stomach intoan oesophagus. The valve member may facilitate swallowing of food fromthe oesophagus into the stomach, and may facilitate vomiting from thestomach into the oesophagus. Thus the valve member may act as a two-wayvalve. Preferably the device is biased towards the closed configuration.Ideally the valve member is configured to be moved from the closedconfiguration to the open configuration upon passage of material throughthe device.

In one case the period of time is greater than 1 secs. Preferably theperiod of time is at least 4 secs. Ideally the period of time is lessthan 20 secs. Most preferably the period of time is not greater than 10secs. The period of time may be between 4 secs and 10 secs.

In one embodiment the valve member comprises a viscoelastic material.Preferably the valve member comprises a foam. Ideally the valve membercomprises a polyurethane material.

In one case the valve member comprises one or more valve leaflets.Preferably the valve leaflet extends substantially radially inwardly.Ideally the valve leaflet is movable between a contracted configurationand an expanded configuration. Most preferably valve leaflet is in thecontracted configuration when the valve member is in the openconfiguration. The valve leaflet may be in the expanded configurationwhen the valve member is in the closed configuration.

In another embodiment the valve member is located proximally of thedistal end of the device. The valve member may be located distally ofthe proximal end of the device.

In another embodiment the device comprises at least one support memberto support the device relative to an oesophagus and/or a stomach.Preferably the support member is located distally of the valve member.Ideally the support member is located proximally of the valve member.Most preferably the support member is arranged co-axially relative tothe valve member. The support member may extend co-axially around thevalve member.

In one case the device comprises a distal support member and a proximalsupport member. Preferably the proximal support member is larger thanthe distal support member. Ideally the radial dimension of the proximalsupport member is larger than the radial dimension of the distal supportmember.

The proximal support member may be substantially of equal size to thedistal support member.

In one case the support member is tapered. Preferably the support membertapers distally radially inwardly.

The support member may taper distally radially outwardly.

The radial dimension of the support member may substantially constantalong the support member.

In one embodiment the support member comprises two or more supportelements. Preferably a first support element is coupled to a secondsupport element. Ideally the region of coupling of the first supportelement to the second support element comprises an articulation region.Most preferably the support element comprises at least one articulationregion intermediate a first coupling region and a second couplingregion. The support element may extend circumferentially in awave-pattern. The support element may extend circumferentially in azig-zag pattern.

In one case the support member comprises a shape memory material.Preferably the support member comprises Nitinol. Ideally the supportmember comprises a stent.

In another case the support member is engagable with a wall of anoesophagus and/or a stomach. The support member may be extendable into awall of an oesophagus and/or a stomach. Preferably the support membercomprises at least one anchor element for anchoring the device to a wallof an oesophagus and/or a stomach. Ideally the anchor element comprisesa pointed tip. The anchor element may be at least partiallysubstantially frusto-conically shaped. The anchor element may be atleast partially substantially bullet shaped.

In one case the support member comprises at least one support ring.Preferably the support member comprises a plurality of support ringsspaced apart along the device. Ideally the support member comprises afirst support ring at a first end of the device and a second supportring at a second end of the device.

In one embodiment the support member is configured to attach the liningdevice to an inner surface of an oesophagus and/or a stomach. Preferablythe support member comprises an adhesive.

The device may comprise a lining member for lining a part of an innersurface of an oesophagus and or a stomach. Preferably the lining memberis located radially outwardly of the valve member. Ideally the liningmember is formed integrally with the valve member. Most preferably thelining member extends distally of the valve member.

The lining member may be located radially outwardly of the supportmember. Preferably the support member extends proximally of the liningmember.

In one case the support member is provided external of the liningmember. The support member may be engagable against an inner surface ofthe lining member. The support member may be at least partially embeddedwithin the lining member. The support member may extend through thelining member.

In another case the device is configured to be located at leastpartially in an oesophagus.

The device may be configured to be located at least partially in astomach.

In one embodiment the device is configured to line around the entirecircumference of a part of an inner surface of an oesophagus and/or astomach. Preferably the device is substantially tubular. Ideally thedevice defines a lumen therethrough. Most preferably at least part ofthe device is movable between an open configuration in which the lumenis open and a sealed configuration in which the lumen is closed. Thedevice may be twistable between the open configuration and the sealedconfiguration. The device may be expandable from the open configurationto the sealed configuration.

In another case the radial dimension of the outer surface of the deviceis substantially constant along the device.

The radial dimension of the outer surface of the device may vary alongthe device. The outer surface of the device may taper inwardly from anend of the device towards the centre of the device. Preferably the outersurface of the device tapers inwardly from each end of the devicetowards the centre of the device.

The radial dimension of the inner surface of the device may vary alongthe device. The inner surface of the device may taper inwardly from anend of the device towards the centre of the device. Preferably the innersurface of the device tapers inwardly from an end of the device towardsthe centre of the device.

In another case the device comprises a sleeve.

The device may be configured to line around only part of thecircumference of a part of an inner surface of an oesophagus and/or astomach. Preferably the device comprises a patch and/or a prosthesis.

In one case the device is configured to deliver a pharmaceutical agentto an inner surface of an oesophagus and/or a stomach. Preferably thelining member is configured to deliver a pharmaceutical agent.

In another embodiment the device has a delivery configuration fordelivery of the device to a deployment location, and a deploymentconfiguration for deployment at the deployment location. Preferably thedevice is contracted in the delivery configuration. Ideally the deviceis expanded in the deployment configuration.

The device may be movable between a first deployment configuration and asecond deployment configuration. Preferably the device is expandablefrom the first deployment configuration to the second deploymentconfiguration. Ideally the device is contractable from the seconddeployment configuration to the first deployment configuration. Mostpreferably the device is biased towards the second deploymentconfiguration. The device may be configured to move from the firstdeployment configuration to the second deployment configuration over apredetermined period of time. Preferably in the first deploymentconfiguration, the device is configured to seal across an oesophaguswith a lower oesophageal sphincter closed. Ideally in the seconddeployment configuration, the device is configured to seal across anoesophagus experiencing transient lower oesophageal sphincterrelaxation.

The device may be at least partially of a polymeric material. The devicemay be at least partially of a viscoelastic foam. At least part of thedevice may be bioabsorbable. At least part of the device may bebiodegradable.

The device may be configured to line a part of an inner surface of anoesophagus. The device may be configured to line a part of an innersurface of a stomach. The device may be configured to line a part of aninner surface of a colon.

In another aspect of the invention there is provided a medical devicesuitable for delivering a therapeutic agent to an alimentary canal, thedevice comprising:—

-   -   a therapeutic agent delivery member;    -   the delivery member comprising at least one pore;    -   the delivery member defining a storage space for storing a        therapeutic agent.

In one embodiment the delivery member is configured to be located in analimentary canal in direct contact with an inner surface of thealimentary canal. Preferably the delivery member is a single layermember. Ideally the delivery member comprises a viscoelastic material.Most preferably the delivery member comprises a foam. The deliverymember may comprise a polyurethane material. Preferably the deliverymember comprises a cellular material.

The diameter of at least one of the cells may be in the range of from0.5 μm to 1000 μm. Preferably the diameter of at least one of the cellsis in the range of from 100 μm to 500 μm.

The storage space may be located in a strut of a cell. The width of thestrut may be in the range of from 1 μm to 200 μm. Preferably the widthof the strut is in the range of from 1 μm to 10 μm.

The density of the delivery member material may be in the range of from10 kg/m³ to 400 kg/m³. Preferably the density of the delivery membermaterial is in the range of from 50 kg/m³ to 150 kg/m³.

In another case the device comprises at least one support member tosupport the delivery member relative to an alimentary canal. Preferablythe support member is configured to attach the delivery member to aninner surface of an alimentary canal. Ideally the support membercomprises an adhesive.

In one case the support member is configured to support the deliverymember lining a part of an inner surface of an alimentary canal. Thesupport member may be provided external of the delivery member. Thesupport member may be engagable against an inner surface of the deliverymember. The support member may be at least partially embedded within thedelivery member. The support member may extend through the deliverymember.

In one case the support member is engagable with a wall of an alimentarycanal. Preferably the support member is extendable into a wall of analimentary canal. Ideally the support member comprises at least oneanchor element for anchoring the delivery member to a wall of analimentary canal. Most preferably the anchor element comprises a pointedtip. The anchor element may be at least partially substantiallyfrusto-conically shaped. The anchor element may be at least partiallysubstantially bullet shaped.

In one embodiment the support member comprises at least one supportring. Preferably the support member comprises a plurality of supportrings spaced apart along the delivery member. Ideally the support membercomprises a first support ring at a first end of the delivery member anda second support ring at a second end of the delivery member.

In another case the delivery member is configured to line around theentire circumference of a part of an inner surface of an alimentarycanal. Preferably the delivery member is substantially tubular. Ideallythe delivery member defines a lumen therethrough.

In another embodiment the radial dimension of the outer surface of thedelivery member is substantially constant along the delivery member.

The radial dimension of the outer surface of the delivery member mayvary along the delivery member. The outer surface of the delivery membermay taper inwardly from an end of the delivery member towards the centreof the delivery member. Preferably the outer surface of the deliverymember tapers inwardly from each end of the delivery member towards thecentre of the delivery member.

The radial dimension of the inner surface of the delivery member mayvary along the delivery member. The inner surface of the delivery membermay taper inwardly from an end of the delivery member towards the centreof the delivery member. Preferably the inner surface of the deliverymember tapers inwardly from each end of the delivery member towards thecentre of the delivery member.

In one case the delivery member comprises a sleeve.

The delivery member may be configured to line around only part of thecircumference of a part of an inner surface of an alimentary canal.Preferably the delivery member comprises a patch and/or a prosthesis.

In another case the device has a delivery configuration for delivery ofthe device through an alimentary canal to a deployment location, and adeployment configuration for deployment at the deployment location.Preferably the device is contracted in the delivery configuration.Ideally the device is expanded in the deployment configuration.

The delivery member may be at least partially of a polymeric material.At least part of the device may be bioabsorbable. At least part of thedevice may be biodegradable.

The device may be configured to deliver a therapeutic agent to a colon.The device may be for delivering a therapeutic agent to an inner surfaceof an alimentary canal. The device may be for delivering a therapeuticagent to an oesophagus. The device may be for delivering a therapeuticagent to a stomach.

In another aspect of the invention there is provided a method ofdelivering a medical treatment device to a treatment location in analimentary canal, the method comprising the steps of:

-   -   providing a medical treatment device;    -   providing a delivery catheter;    -   locating the medical treatment device at least partially within        the delivery catheter;    -   advancing the delivery catheter through an alimentary canal; and    -   deploying the medical treatment device out of the delivery        catheter at a treatment location in the alimentary canal

In one embodiment the method comprises the step of collapsing at leastpart of the medical treatment device before locating at least partiallywithin the delivery catheter. Preferably the medical treatment device iscollapsed into a folded configuration. By collapsing the medicaltreatment device into the folded configuration, this provides for alow-profile when the medical treatment device is collapsed.

The medical treatment device may be located within the delivery catheterby drawing the medical treatment device at least partially into thedelivery catheter. The medical treatment device may be located withinthe delivery catheter by advancing at least part of the deliverycatheter relative to the medical treatment device.

In one case the method comprises the steps of:—

-   -   providing a medical guidewire; and    -   advancing the medical guidewire through the alimentary canal.

Preferably the delivery catheter is advanced over the medical guidewire.The medical guidewire may act as a guide path for the delivery of thedelivery catheter through the alimentary canal.

The medical treatment device may be deployed by retracting at least partof the delivery catheter relative to the medical treatment device. Themedical treatment device may be deployed by advancing at least part ofthe delivery catheter relative to the medical treatment device.

In one embodiment the medical treatment device expands after deploymentout of the delivery catheter. Preferably the medical treatment deviceself-expands upon deployment out of the delivery catheter.

In another case the method comprises the steps of:—

-   -   providing a deployment aid member; and    -   locating the deployment aid member between the medical treatment        device and the delivery catheter.

The deployment aid member may minimise frictional forces acting betweenthe medical treatment device and the delivery catheter. In this waydeployment of the medical treatment device out of the delivery cathetermay be eased. Similarly loading of the medical treatment device into thedelivery catheter may be eased.

Preferably the method comprises the step of deploying the deployment aidmember out of the delivery catheter at the treatment location. Ideallythe deployment aid member is deployed upon deployment of the medicaltreatment device.

In another embodiment the method comprises the step of, after deployingthe medical treatment device out of the delivery catheter, locating themedical treatment device at least partially within the deliverycatheter. By locating the medical treatment device within the deliverycatheter for a second time, this enables the location of the medicaltreatment device to be moved or adjusted to a second treatment location.Preferably the method comprises the step of moving the delivery catheterthrough the alimentary canal. Ideally the method comprises the step ofdeploying the medical treatment device out of the delivery catheter at asecond treatment location in the alimentary canal.

In one case the method comprises the step of withdrawing the deliverycatheter from the alimentary canal.

The method may be a method of delivering a medical treatment device to atreatment location in an oesophagus.

The method may be a method of delivering a medical treatment device to atreatment location in a stomach.

The invention also provides in a further aspect a delivery system fordelivering a medical treatment device to a treatment location in analimentary canal, the system comprising:—

-   -   a delivery catheter;    -   the delivery catheter comprising a reception space into which a        medical treatment device may by at least partially located.

In one embodiment the delivery catheter has a delivery configuration fordelivery of a medical treatment device through an alimentary canal to atreatment location, and a deployment configuration for deployment of themedical treatment device at the treatment location.

The delivery catheter may comprise an outlet from the reception spacethrough which a medical treatment device is passable for deployment ofthe medical treatment device. Preferably the delivery catheter comprisesa shoulder adjacent to the outlet. Ideally the shoulder extends radiallyoutwardly. Most preferably the shoulder extends around the circumferenceof the delivery catheter.

In one case at least part of the delivery catheter is retractablerelative to a medical treatment device to deploy the medical treatmentdevice out of the delivery catheter. Preferably the part of the deliverycatheter comprises a sheath.

In another case at least part of the delivery catheter is advanceablerelative to a medical treatment device to deploy the medical treatmentdevice out of the delivery catheter. Preferably the part of the deliverycatheter comprises a pusher.

The delivery catheter may comprise an ejector movable between thedelivery configuration and the deployment configuration to deploy amedical treatment device out of the reception space.

The delivery catheter may comprise an expandable portion. Preferably amedical treatment device is mountable over the expandable portion.Ideally the expandable portion is contracted in the deliveryconfiguration. The expandable portion may be expanded in the deploymentconfiguration.

In one case the delivery catheter comprises a cover element. Preferablyin the delivery configuration the cover element extends over a medicaltreatment device to cover the medical treatment device. Ideally in thedelivery configuration the cover element restrains a medical treatmentdevice. In the deployment configuration the cover element may beretracted to uncover a medical treatment device.

In another case the system comprises a deployment aid member forlocation between a medical treatment device and the delivery catheter.Preferably the deployment aid member is coupled to a medical treatmentdevice. Ideally the deployment aid member comprises a low co-efficientof friction material. The deployment aid member may be substantiallytubular. Preferably the deployment aid member comprises a sleeve.Ideally the deployment aid member comprises a biodegradable material.

In one case the system comprises a medical guidewire. Preferably thedelivery catheter is advanceable over the medical guidewire.

The system may be a delivery system for delivering a medical treatmentdevice to a treatment location in an oesophagus.

The system may be a delivery system for delivering a medical treatmentdevice to a treatment location in a stomach.

In a further aspect of the invention there is provided a kitcomprising:—

-   -   a medical treatment device; and    -   a delivery system for delivering the medical treatment device to        a treatment location in an alimentary canal of the invention

In one case the medical treatment device is movable between a collapsedconfiguration and an expanded configuration. Preferably the medicaltreatment device is substantially folded in the collapsed configuration.Ideally the medical treatment device is biased towards the expandedconfiguration.

The medical treatment device may comprise a device of the invention.

The medical treatment device of the invention solves the problemsassociated with one-way valves as it is designed to allow flow in bothdirections. In one embodiment the device does not actually occlude theoesophageal lumen completely but merely adds bulk around the sphincterto augment the natural function of the muscle. It may mechanically mimicthe action of the native oesophageal tissue in that it compresses,distends and relaxes in a similar fashion, thus lending itself tofunction in a ‘physiologically mimetic’ fashion. Because the device isphysiologically mimetic it does not need to invert or change orientationthus representing a significant improvement. The device may act as aprosthetic sphincter insert.

The invention provides a mechanism for the control of drug release froma biomaterial. The invention does not need to have multiple layers ofmaterial to control drug release.

The invention is not invasive and is not placed into tissue. Rather theinvention is located on the surface of tissue.

The medical treatment device of the invention is not elastic, but rathermimics the characteristics of the native tissue. The device does notpenetrate the oesophageal tissue and thus does not cause injury to thetissue.

According to another aspect of the invention there is provided a medicaldevice comprising means for lining a part of an inner surface of analimentary canal. By lining part of the inner surface of the alimentarycanal, this enables the alimentary canal to be treated.

In one embodiment of the invention the device comprises means to supportthe lining means lining a part of an inner surface of an alimentarycanal. By supporting the lining means, this assists in maintaining thelining means in the desired location and in resisting dislodgement ofthe lining means, for example due to peristaltic motion of thealimentary canal or to food passing through the alimentary canal.Preferably the support means comprises means to attach the lining meansto an inner surface of an alimentary canal. Ideally the attachment meanscomprises an adhesive.

In one case the support means comprises a support element for supportingthe lining means lining a part of an inner surface of an alimentarycanal. Preferably the support element is provided external of the liningmeans. Ideally the support element is engagable against an inner surfaceof the lining means. The support element may be at least partiallyembedded within the lining means. The support element may extend throughthe lining means. The support element may be engagable with a wall of analimentary canal. Preferably the support element is extendable into awall of an alimentary canal. Ideally the support element comprises atleast one anchor element for anchoring the lining means to a wall of analimentary canal. Most preferably the anchor element comprises a pointedtip. The anchor element may be at least partially substantiallyfrusto-conically shaped. The anchor element may be at least partiallysubstantially bullet shaped.

In one embodiment the support element comprises at least one supportring. Preferably the support element comprises a plurality of supportrings spaced apart along the lining means. Ideally the support elementcomprises a first support ring at a first end of the lining means and asecond support ring at a second end of the lining means.

In another case the lining means is configured to line around the entirecircumference of a part of an inner surface of an alimentary canal.Preferably the lining means is substantially tubular. Ideally the liningmeans defines a lumen therethrough. Most preferably at least part of thelining means is movable between an open configuration in which the lumenis open and a sealed configuration in which the lumen is closed. Whenthe lining means is in the sealed configuration, the lumen is closeddown. The medical device may therefore be employed as an artificialmuscle, for example as an artificial sphincter, for example at thejunction of the oesophagus and the stomach to prevent acid reflux fromthe stomach. The medical device may function as a mechanical device toreplace the working of the original muscle. The lining means may betwistable between the open configuration and the sealed configuration.Preferably the lining means is expandable from the open configuration tothe sealed configuration.

The radial dimension of the outer surface of the lining means may besubstantially constant along the lining means. The radial dimension ofthe outer surface of the lining means may vary along the lining means.The outer surface of the lining means may taper inwardly from an end ofthe lining means towards the centre of the lining means. Preferably theouter surface of the lining means tapers inwardly from each end of thelining means towards the centre of the lining means.

The radial dimension of the inner surface of the lining means may varyalong the lining means. Preferably the inner surface of the lining meanstapers inwardly from an end of the lining means towards the centre ofthe lining means. Ideally the inner surface of the lining means tapersinwardly from each end of the lining means towards the centre of thelining means.

In another embodiment the lining means comprises a sleeve.

In one case the lining means is configured to line around only part ofthe circumference of a part of an inner surface of an alimentary canal.Preferably the lining means comprises a patch and/or a prosthesis.

In one embodiment the device comprises means to deliver a pharmaceuticalagent to an inner surface of an alimentary canal. A function of themedical device may be to deliver pharmaceuticals to the inner surface orlining of the alimentary canal. By delivering the pharmaceutical agentto the inner surface of the alimentary canal, this arrangement enablesfocussed, localised drug delivery to be achieved to optimise treatmentand minimise any undesirable side-effects of the pharmaceutical agent.Preferably the lining means comprises the means to deliver thepharmaceutical agent.

In another case the lining means has a delivery configuration fordelivery of the lining means through an alimentary canal to a deploymentlocation and a deployment configuration for deployment at the deploymentlocation. In the delivery configuration, the lining means may have alow-profile configuration for ease of navigation through the alimentarycanal. Preferably the lining means is contracted in the deliveryconfiguration. Ideally the lining means is expanded in the deploymentconfiguration.

In one embodiment the lining means is movable between a first deploymentconfiguration and a second deployment configuration. Preferably thelining means is expandable from the first deployment configuration tothe second deployment configuration. Ideally the lining means iscontactable from the second deployment configuration to the firstdeployment configuration. Most preferably the lining means is biasedtowards the second deployment configuration. The lining means may beconfigured to move from the first deployment configuration to the seconddeployment configuration upon elapse of a predetermined period of time.Preferably in the first deployment configuration, the lining means isconfigured to seal across an oesophagus with a lower oesophagealsphincter closed. Ideally in the second deployment configuration, thelining means is configured to seal across an oesophagus experiencingtransient lower oesophageal sphincter relaxation.

The lining means may be at least partially of a polymeric material. Thelining means may be at least partially of a viscoelastic foam. At leastpart of the device may be bioabsorbable. At least part of the device maybe biodegradable.

The lining means may be configured to line a part of an inner surface ofan oesophagus. The lining means may be configured to line a part of aninner surface of a stomach. The lining means may be configured to line apart of an inner surface of a colon.

In another aspect the invention provides a delivery device fordelivering a medical device to a deployment location in an alimentarycanal, the device having a delivery configuration for delivery of themedical device through the alimentary canal to the deployment location,and a deployment configuration for deployment of the medical device atthe deployment location. In the delivery configuration, the deliverydevice may have a low-profile configuration for ease of navigationthrough the alimentary canal.

In one embodiment in the delivery configuration the device comprises areception space for receiving a medical device. Preferably the devicecomprises an outlet from the reception space through which a medicaldevice is passable for deployment of the medical device. Ideally thedevice comprises a shoulder adjacent to the outlet. The shoulder of thedelivery device acts to push the walls of the alimentary canal outwardlyto ease deployment of the medical device. Most preferably the shoulderextends radially outwardly. The shoulder may extend around thecircumference of the device.

In one case the device comprises an ejector movable between the deliveryconfiguration and the deployment configuration to deploy a medicaldevice out of the reception space.

The device may comprise an expandable portion. Preferably a medicaldevice is mountable over the expandable portion. Ideally the expandableportion in contracted in the delivery configuration. Most preferably theexpandable portion is expanded in the deployment configuration.

The device may comprise a cover element. Preferably in the deliveryconfiguration the cover element extends over a medical device to coverthe medical device. Ideally in the delivery configuration the coverrestrains a medical device. Most preferably in the deploymentconfiguration the cover element is retracted to uncover a medicaldevice.

In one case the device is configured to deliver a medical device to adeployment location in an oesophagus. The device may be configured todeliver a medical device to a deployment location in a stomach. Thedevice may be configured to deliver a medical device to a deploymentlocation in a colon.

The invention also provides in a further aspect a kit comprising:—

-   -   a medical device of the invention; and    -   a delivery device for delivering the medical device to a        deployment location in an alimentary canal.

In one embodiment the delivery device comprises a device of theinvention.

According to another aspect of the invention there is provided a methodof treating an alimentary canal comprising the step of lining a part ofan inner surface of the alimentary canal.

In one embodiment a lining means is supported lining part of the innersurface of the alimentary canal. Preferably the lining means is attachedto the inner surface of the alimentary canal.

The method may comprise the step of engaging a support element with awall of the alimentary canal. Preferably the support element is extendedinto the wall of the alimentary canal. Ideally the lining means isanchored to the wall of the alimentary canal.

In one case the lining means is moved between an open configuration inwhich a lumen through the lining means is open, and a sealedconfiguration in which the lumen is closed.

In another embodiment the method comprises the step of delivering apharmaceutical agent to the inner surface of the alimentary canal.

The method may comprise the step of delivering the lining means throughthe alimentary canal to a deployment location. Preferably the methodcomprises the step of deploying the lining means at the deploymentlocation to line part of the inner surface of the alimentary canal.Ideally the lining means is deployed by expanding the lining means. Mostpreferably the lining means is deployed by passing the lining means outof a reception space of a delivery device. The lining means may bedeployed by retracting a cover element of a delivery device to uncoverthe lining means.

In one case the invention provides a method of treating an oesophagus.The invention may provide a method of treating an oesophagusexperiencing transient lower oesophageal sphincter relaxation.

In another case the invention provides a method of treating a stomach.

The invention may provide a method of treating a colon.

A function of the medical device may be for wound healing. The inventionmay provide a means of protecting injured gastric tissue for weeks ormonths to enable healing.

The invention may provide a system for applying an endoluminal gastriccoating.

The invention may provide a device, which is introduced into thegastrointestinal tract using an endoscope. The device may incorporate ameans of placing a soft polymeric covering or lining onto thegastrointestinal surface or epithelium. The covering or lining may bemade from an adhesive gel type material, such as hydrogel, silicone,chitosan gel or alginate gel, or polyurethane foams. The covering orlining may comprise an overlayer that prevents displacement of theprosthesis due to digestive processes. The overlayer may be a polymericfilm or a metal spring clip. The polymeric covering or lining may beloaded with a drug to treat a specific underlying disease state, such asan ulcer, tumour or surgery induced scar. The prosthesis may be tailoredto degrade over a preset period of time facilitating its removal fromthe body.

The invention may provide a device designed to be attached to anendoscope for treatment of gastrointestinal diseases. The device mayhave a degradable adhesive polymer prosthesis, and a mechanism forattachment of the prosthesis to the gastric mucosa. The prosthesis maycontain a pharmaceutical compound for localised drug delivery.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the followingdescription of some embodiments thereof, given by way of example only,with reference to the accompanying drawings, in which:—

FIG. 1 is an isometric view of a medical device according to theinvention mounted to a delivery device according to the invention;

FIGS. 2 to 5 are partially cut-away, isometric views of the medicaldevice and the delivery device of FIG. 1, in use;

FIG. 6 is a partially cut-away, isometric view of another medical deviceaccording to the invention, in use;

FIG. 7 is a cross-sectional, side view of another medical deviceaccording to the invention mounted to another delivery device accordingto the invention, in use;

FIGS. 8 to 10 are isometric views of the medical device and the deliverydevice of FIG. 7, in use;

FIG. 10(a) is a cross-sectional, side view of another medical deviceaccording to the invention deployed in an alimentary canal;

FIGS. 10(b) to 10(h) are cross-sectional, side views of the medicaldevice of FIG. 10(a), in use;

FIG. 10(i) is a cut-away, isometric view of another medical deviceaccording to the invention;

FIG. 10(j) is a cut-away, isometric view of a further medical deviceaccording to the invention;

FIG. 11 is an isometric view of another medical device according to theinvention;

FIG. 12 is an isometric view of a further medical device according tothe invention;

FIG. 13 is a partially cut-away, isometric view of another medicaldevice according to the invention passing out of another delivery deviceaccording to the invention;

FIG. 14 is a partially cut-away, isometric view of the medical deviceand the delivery device of FIG. 13, in use;

FIGS. 15 to 17 are cross-sectional, side views of another medical deviceaccording to the invention, in use;

FIGS. 17(a) and 17(b) are cross-sectional, side views of another medicaldevice according to the invention, in use;

FIG. 17(d) is a cross-sectional, plan view of a further medical deviceaccording to the invention deployed in an alimentary canal;

FIG. 17(e) is an isometric view of an anchor element of the medicaldevice of FIG. 17(d);

FIG. 17(f) is a cross-sectional, plan view of the medical device of FIG.17(d) anchored to a wall of the alimentary canal;

FIGS. 18 to 21 are isometric views of a further medical device accordingto the invention, in use;

FIGS. 22 to 25 are plan views corresponding to FIGS. 18 to 21respectively of the medical device;

FIG. 26 is a cross-sectional, side view of a medical treatment deviceaccording to the invention;

FIG. 27 is an isometric view of a support member of the device of FIG.26;

FIG. 28 is a side view of the support member of FIG. 27;

FIG. 29 is an enlarged, side view of a part of the support member ofFIG. 28;

FIG. 30 is a plan view of the support member of FIG. 27;

FIG. 31 is a schematic illustration of the material of the device ofFIG. 26;

FIG. 32 is an enlarged, schematic illustration of the material of FIG.31;

FIG. 32(a) is a photographic representation of the material of FIG. 31;

FIGS. 33 and 34 are views similar to FIGS. 31 and 32 of the material ofanother medical treatment device according to the invention;

FIG. 35 is an isometric view of a delivery catheter of a delivery systemaccording to the invention;

FIG. 36 is a partially cut-away, isometric view of the delivery catheterof FIG. 35 and the device of FIG. 26;

FIG. 37 is an isometric view of the device of FIG. 36;

FIG. 38 is an end view of the device of FIG. 37;

FIGS. 39 and 40 are isometric views of the delivery catheter of FIG. 35and the device of FIG. 26, in use;

FIGS. 41 to 43 are side views of the delivery catheter of FIG. 35 andthe device of FIG. 26, in use;

FIGS. 44 to 49 are isometric views of the delivery catheter of FIG. 35and the device of FIG. 26, in use;

FIGS. 50 to 54 are cross-sectional, side views of the device of FIG. 26,in use;

FIGS. 55 to 60 are further cross-sectional, side views of the device ofFIG. 26, in use;

FIGS. 61 to 72 are cross-sectional, side views of other medicaltreatment devices according to the invention;

FIG. 73 is an enlarged, cross-sectional, side view of a part of thedevice of FIG. 72;

FIG. 74 is a plan view of the device of FIG. 72;

FIG. 75 is an isometric view of another medical treatment deviceaccording to the invention;

FIG. 76 is a side view of the device of FIG. 75;

FIG. 77 is a view along line A-A in FIG. 76;

FIG. 78 is a plan view of the device of FIG. 75;

FIGS. 79 to 82 are views similar to FIGS. 75 to 78 of another medicaltreatment device according to the invention;

FIGS. 83 to 86 are views similar to FIGS. 75 to 78 of a further medicaltreatment device according to the invention;

FIGS. 87 to 90 are views similar to FIGS. 75 to 78 of another medicaltreatment device according to the invention;

FIGS. 91 to 94 are views similar to FIGS. 75 to 78 of another medicaltreatment device according to the invention;

FIGS. 95 to 98 are views similar to FIGS. 75 to 78 of a further medicaltreatment device according to the invention;

FIGS. 99 to 101 and 103 are views similar to FIGS. 27 to 30 of a supportmember of another medical treatment device according to the invention;

FIG. 102 is an enlarged, side view of a part of the support member ofFIG. 100;

FIGS. 104 to 107 and 110 are views similar to FIGS. 99 to 103 of asupport member of a further medical treatment device according to theinvention;

FIG. 108 is another side view of the support member of FIG. 104; and

FIG. 109 is an enlarged, side view of a part of the support member ofFIG. 108.

DETAILED DESCRIPTION

Referring to the drawings, and initially to FIGS. 26 to 60 thereof,there is illustrated a medical treatment device 200 according to theinvention. The device 200 is suitable for treating reflux from a stomach201 to an oesophagus 202. The device 200 is also suitable for deliveringa therapeutic agent to an inner surface of an alimentary canal, forexample to the oesophagus 202 and/or to the stomach 201.

The device 200 comprises a valve member 203, a lining member 204 forlining part of the inner surface of the oesophagus 202 and/or thestomach 201, and a proximal support member 205 to support the device 200relative to the oesophagus 202 and the stomach 201.

The valve member 203 is located proximally of the distal end of thedevice 200, and distally of the proximal end of the device 200.

The valve member 203 is movable between a closed configuration (FIG. 50)and an open configuration (FIG. 52). In the open configuration, thevalve member 203 facilitates passage of material, such as food, from theoesophagus 202 into the stomach 201, and facilitates passage ofmaterial, such as vomit, from the stomach 201 into the oesophagus 202.

The valve member 203 comprises two valve leaflets 206 extending radiallyinwardly. The valve leaflets 206 are movable between an expandedconfiguration (FIG. 50) and a contracted configuration (FIG. 52). Whenthe valve member 203 is in the closed configuration, the valve leaflets206 are in the expanded configuration (FIG. 50). When the valve member203 is in the open configuration, the valve leaflets 206 are in thecontracted configuration (FIG. 52).

The valve member 203 may be moved from the closed configuration (FIG.50) to the open configuration (FIG. 52) by passage of material, such asfood, through the device 200. In particular, the food is forced throughthe oesophagus 202 by means of peristalsis. When the food reaches thevalve member 203, the food engages the valve leaflets 206 and compressesthe valve leaflets 206 from the expanded configuration to the contractedconfiguration. The food then passes through the open valve member 203into the stomach 201.

The valve member 203 is of a viscoelastic, polyurethane foam material.The valve member 203 is biased towards the closed configuration. Howeverbecause of the viscoelastic nature of the valve member 203, the valveleaflets 206 do not move immediately from the contracted configurationto the expanded configuration. Rather, after the food has passed throughthe valve member 203, the valve leaflets 206 gradually move over aperiod of 4 to 10 seconds from the contracted configuration to theexpanded configuration, as illustrated in FIGS. 52 to 54. Thus the valvemember 203 gradually moves from the open configuration to the closedconfiguration over a period of 4 to 10 seconds.

The material of the valve member 203 may have the followingcharacteristics:

-   -   the material may be viscoelastic;    -   the material may be a biomaterial;    -   the material may have shape memory;    -   the material may be a cellular material;    -   the material may be open cell or closed cell;    -   the material may have gas voids incorporated;    -   the material may be hydrolytically and oxidatively stable;    -   the material may be biomimetic;    -   the material may be biocompatible;    -   the material may be biostable;    -   the material may be a polymer.

The support member 205 is located proximally of the valve member 203.

The support member 205 tapers distally radially inwardly. In this mannerthe support member 205 acts as a funnel to guide material, such as food,from the oesophagus 202 towards the valve member 203.

As illustrated in FIGS. 27 to 30, the support member 205 is provided inthe form of a stent. In particular the support member 205 comprises twosupport elements 207.

Each support element 207 extends circumferentially in a zig-zag, wavepattern. The support elements 207 are coupled to one another. Eachregion of coupling of the two support elements 207 to one another actsas an articulation region 208 (FIG. 29).

Each support element 207 is of a shape memory material, such as Nitinol.

FIGS. 27 to 30 illustrate the retention mechanism with a singlearticulation. FIG. 29 illustrates the articulation feature.

The angle α may be in the range of from 170° to 70°. The radius ofcurvature at this angle α may be in the range of from 0.9 mm to 0.1 mm.

The angle β may be in the range of from 95° to 5°. The radius ofcurvature at this angle β may be in the range of from 0.9 mm to 0.1 mm.

The lining member 204 is formed integrally with the valve member 203.The lining member. 204 is located radially outwardly of the valve member203 and extends distally of the valve member 203 in a substantiallycylindrical tube shape. The lining member 204 is located radiallyoutwardly of the support member 205 and extends proximally of the valvemember 203. In this case the lining member 204 terminates at theproximal end of the support member 205.

When the device 200 is deployed, the lining member 204 is in directcontact with the inner surface of the oesophagus 202/stomach 201. Thelining member 204 may be employed for delivery of a therapeutic agent tothe oesophagus 202/stomach 201. In particular the lining member 204comprises a single layer of a viscoelastic, polyurethane foam material.This material is a cellular material and comprises a plurality of pores.A therapeutic agent 209 may be stored in the struts 210 of the cells.The therapeutic agent 209 may also be stored in the pores, however thestruts 209 are the primary location for storing the therapeutic agent209. FIG. 32(a) illustrates the cellular structure of the foam.

The size of the cells may vary, for example the diameter of the cellsmay be in the range of from 0.5 μm to 1000 μm, preferably in the rangeof from 100 μm to 500 μm. Similarly the size of the structure may vary,for example the width of the struts 210 may be in the range of from 1 μmto 200 μm, preferably in the range of from 1 μm to 10 μm. Furthermorethe density of the material may vary, for example the density of thematerial may be in the range of from 10 kg/m³ to 400 kg/m³, preferablyin the range of from 50 kg/m³ to 150 kg/m³.

The material of the lining member 204 may have the followingcharacteristics:

-   -   the material may be viscoelastic;    -   the material may be a biomaterial;    -   the material may have shape memory;    -   the material may be a cellular material;    -   the material may be open cell or closed cell;    -   the material may have gas voids incorporated;    -   the material may be hydrolytically and oxidatively stable;    -   the material may be biomimetic;    -   the material may be biocompatible;    -   the material may be biostable;    -   the material may be a polymer.

Drug delivery to the inner lumen of the alimentary canal is a technicalchallenge for a number of reasons. The alimentary canal is a dynamicmuscular structure that functions very efficiently to propel occludingitems such as food through its length. Also, much of the tissue in thealimentary canal exhibits viscoelastic behaviour. This causes the tissueto relax slowly in response to an expansion caused by the passage offood. This makes it difficult to maintain a drug delivery system incontact with the endothelium for prolonged periods. Furthermore, theupper part of the alimentary canal, especially the oesophagus is poorlyperfused relative to other areas of the body. This makes the systemicdelivery of drugs to target the oesophageal tissue an inefficient meansof achieving the correct bio-distribution.

The invention achieves drug delivery through the endothelium of theoesophagus by topical administration, i.e. applied directly to a part ofthe body. The invention maintains uninterrupted intimate contact withthe endothelium, for the required duration of treatment. The inventioncarries sufficient quantity of the therapeutic agent, and delivers thisat a rate appropriate to the indication being treated.

The medical treatment device of the invention has mechanical propertiessimilar to the oesophagus. This ensures that there are no periods ofendothelial non-contact and thus no interrupted drug release. Theinvention matches the viscoelastic/mechanical properties of the tissuein order to ensure uninterrupted dosage.

In the case where it is necessary to deliver a drug to a site close to adysfunctional sphincter, the invention enables drug delivery from theouter surface of the anti-reflux valve to be used.

The medical treatment device of the invention may comprise a structuremade from a material that mimics the mechanical properties of thegastrointestinal tract. The viscoelastic behaviour of this structureenables constant contact without the need for adhesive attachment. Themedical treatment device of the invention may be a cellular foam, thestructure and geometry of which may be altered to present a variety ofsurface areas available for direct contact.

The rate of drug release may be controlled through variation of cellularstructure. The surface area may be used as a means of achieving theoptimum drug release kinetics. This approach has the additional benefitthat diffusion control layers and the like are no longer necessary. Thedrug will be situated within the cell struts 210 as illustrated in FIGS.31 and 32 and thus the dimensions of these struts 210 and theconcentration of drug contained therein will influence the kineticrelease properties.

FIGS. 31 to 34 are schematic representations of drug molecules in foamswith struts 210 of different dimensions. FIG. 32 illustrates the largecell struts 210 with greater drug loading and the drug molecules 209.FIG. 34 illustrates the small cell struts 210 with lower drug loading.

The foam cells may be between 0.5 and 1000 μm in diameter but ideallybetween 100 and 500 μm in diameter. The width of the struts 210 (orwalls) of the cells may be between 1 μm and 200 μm but more preferablybetween 1 μm and 10 μm.

The density of the foam may be between 10 Kg/M³ and 400 Kg/M³ but morepreferably between 50 Kg/M³ and 150 Kg/M³.

The compression and hysteresis behaviour of the foam material may besimilar to that of human oesophageal tissue.

The medical treatment device of the invention may be used to deliver avariety of therapeutic agents including low molecular weight drugs suchas H2 receptor antagonists, proton pump inhibitors or high molecularweight drugs such as proteins and peptides. In addition gene and cellbased therapies may be delivered. Exemplary non-genetic therapeuticagents include anti-neoplastic/anti-proliferative/anti-mitotic agentssuch as paclitaxel, epothilone, cladribine, 5-fluorouracil,methotrexate, doxorubicin, daunorubicin, cyclosporine, cisplatin,vinblastine, vincristine, epothilones, endostatin, trapidil,halofuginone, and angiostatin; anti-cancer agents such as antisenseinhibitors of c-myc oncogene; anti-microbial agents such as triclosan,cephalosporins, aminoglycosides, nitrofurantoin, silver ions, compounds,or salts; biofilm synthesis inhibitors such as non-steroidalanti-inflammatory agents and chelating agents such asethylenediaminetetraacetic acid, O,O′-bis(2-aminoethyl)ethyleneglycol-N,N,N′N′-tetraacetic acid andmixtures thereof; antibiotics such as gentamycin, rifampin, minocyclin,and ciprofolxacin; antibodies including chimeric antibodies and antibodyfragments; anesthetic agents such as lidocaine, bupivacaine, andropivacaine; nitric oxide; nitric oxide (NO) donors such as lisidomine,molsidomine, L-arginine, NO-carbohydrate adducts, polymeric oroligomeric NO adducts; and any combinations and prodrugs of the above.

Exemplary biomolecules include peptides, polypeptides and proteins;oligonucleotides; nucleic acids such as double or single stranded DNA(including naked and cDNA), RNA, antisense nucleic acids such asantisense DNA and RNA, small interfering RNA (siRNA), and ribozymes;genes; carbohydrates; angiogenic factors including growth factors; cellcycle inhibitors. Nucleic acids may be incorporated into deliverysystems such as, for example, vectors (including viral vectors),plasmids or liposomes.

Exemplary small molecules include hormones, nucleotides, amino acids,sugars, and lipids and compounds have a molecular weights of less than100 kD.

Exemplary cells include stem cells, progenitor cells, endothelial cells,adult cardiomyocytes, and smooth muscle cells. Cells can be of humanorigin (autologous or allogenic) or from an animal source (xenogenic),or genetically engineered. Non-limiting examples of cells includemesenchymal stem cells including mesenchymal stem cells with 5-aza, cordblood cells, endothelial progenitor cells, skeletal myoblasts orsatellite cells, muscle derived cells, go cells, endothelial cells,genetically modified cells, tissue engineered grafts, embryonic stemcell clones, embryonic stem cells, fetal or neonatal cells,immunologically masked cells, and teratoma derived cells.

FIG. 26 illustrates the reflux device 200 positioned at the loweroesophageal sphincter. FIG. 26 illustrates the esophagus 202, loweresophageal sphincter (LES) 300, crural diaphragm 301, angle of His 302,anti-reflux device lumen 303, anti-reflux device barrier 203, cruraldiaphragm 304, retention mechanism 205.

The length of the support member 205 is less than the wavelength ofperistalsis. The typical peristalsis wavelength at the proximaloesophagus is 4.9 cm, at the mid oesophagus is 8.8 cm, and at the distaloesophagus is 6.8 cm.

In FIGS. 35 to 49 there is illustrated a delivery system according tothe invention. The delivery system is suitable for delivering the device200 to a treatment location in the alimentary canal, for example in theoesophagus 202 or in the stomach 201.

The delivery system comprises a delivery catheter 211, a medicalguidewire 212, and a tubular sleeve 400 of a low co-efficient offriction material.

The delivery catheter 211 comprises a restraining sheath 213 and anelagate body element 214. The sheath 213 is movable relative to the bodyelement 214 between a delivery configuration (FIG. 39) for delivery ofthe device 200 through the oesophagus 202 to the treatment location, anda deployment configuration (FIG. 40) for deployment of the device 200 atthe treatment location. In the delivery configuration, the deliverycatheter 211 defines a reception space 215 into which the device 200 islocated. In the deployment configuration, the sheath 213 is retractedrelative to the body element 214 to facilitate deployment of the device200 out of the reception space 215.

The device 200 is movable between a collapsed, folded configuration(FIG. 37) and an expanded configuration (FIG. 40). The device 200 islocated in the reception space 215 in the collapsed configuration. Thedevice 200 is biased towards the expanded configuration.

The distal tip 216 of the body element 214 tapers proximally radiallyoutwardly to provide a smooth crossing profile at the distal end of thedelivery catheter 211.

The delivery catheter 211 may be advanced through the oesophagus 202over the guidewire 212.

The low-friction sleeve 400 is coupled to the device 200 (FIG. 37). Whenthe device 200 is located in the reception space 215, the low-frictionsleeve 400 is located between the device 200 and the internal wall ofthe sheath 213. Because of the low co-efficient of friction material,the low-friction sleeve 400 acts as an aid to ease deployment of thedevice 200 from the reception space 215, and also act as an aid to easeloading of the device 200 into the reception space 215.

The sleeve 400 is a biodegradable material.

FIGS. 35 to 38 illustrate:

-   -   anti-reflux device delivery system with tapered tip 216 and        overtube 213 arrangement (FIG. 35)    -   interior detail of how anti-reflux device 200 is stored in        folded/pleated configuration (FIG. 36)    -   detail of anti-reflux device 200 folding pattern (FIG. 37)    -   alginate or other biodegradable polymer wrapper (FIG. 38).

FIG. 37 is an isometric view of the crimped device 200.

FIGS. 39 and 40 are isometric illustrations showing the mechanism of thedevice deployment whereby an outer tube transfers a force to the distalend of the system thus retracting the overtube 213 and releasing thedevice 200 which quickly takes its native shape. FIGS. 39 and 40 areisometric views of deployment.

FIGS. 41 to 43 illustrate:

-   -   delivery system fully loaded (FIG. 41)    -   overtube 213 partially retracted from over anti-reflux device        200 revealing pleated/folded configuration (FIG. 42)    -   overtube 213 fully retracted from over anti-reflux device 200        with device 200 fully deployed (FIG. 43).

FIGS. 41 to 43 are elevation views of deployment.

FIGS. 44 to 49 illustrate:

-   -   delivery catheter 211 placed in the oesophagus 202 with a        guidewire 212 running through a central lumen of the delivery        system (FIG. 44).    -   overtube 213 retracting from over anti-reflux device 200        revealing pleated/folded configuration (FIGS. 45 to 47).    -   anti-reflux device 200 deployed into the oesophagus 202 with        retention mechanism 205 engaging with inner lumen and        endothelium (FIG. 48).    -   device 200 deployed and delivery system being retracted with        tapered tip 216 passing through the centre of the anti-reflux        device barrier 203 (FIG. 49).

FIGS. 44 to 49 are isometric views of the device 200 being deployed insitu.

In use, the device 200 is collapsed to the folded configuration (FIG.37). The device 200, with the low-friction sleeve coupled thereto, islocated in the reception space 215. The sheath 213 is advanced relativeto the body element 214 over the collapsed device 200 to restrain thedevice 200. The low-friction sleeve acts to minimise frictional forcesduring advancement of the sheath 213 over the device 200.

The guidewire 212 is advanced through the oesophagus 202 until thedistal end of the guidewire 212 is within the stomach 201. The deliverycatheter 211 in the delivery configuration is advanced over theguidewire 212 until the collapsed device 200 is at the desired treatmentlocation, for example at the oesophageal sphincter (FIG. 44).

The sheath 213 is then retracted while maintaining the position of thebody element 214 substantially fixed (FIGS. 45 to 47). In this mannerthe device 200 is uncovered. The device 200 self-expands to the expandedconfiguration engaging the inner wall of the oesophagus 202 (FIG. 48).Part of the device 200 is located in the oesophagus 202 and part of thedevice 200 extends into the stomach 201. The delivery catheter 211 maythen be withdrawn from the oesophagus 202 leaving the device 200 in thedesired treatment location (FIG. 49).

The low-friction sleeve is deployed out of the reception space 215 upondeployment of the device 200. Over time the sleeve biodegrades.

FIGS. 50 to 54 illustrate the device 200 in use in the case where theoesophageal sphincter fails to close effectively to prevent reflux fromthe stomach 201 to the oesophagus 202. When the valve member 203 is inthe closed configuration, reflux from the stomach 201 to the oesophagus202 is prevented (FIG. 50). As food passes through the oesophagus 202and into the device 200, the food forces the valve leaflets 206 to thecontracted configuration (FIG. 52). When the valve member 203 is in theopen configuration, the food may pass through the valve member 203 intothe stomach 201. After the food has passed through the valve member 203,the valve leaflets 206 gradually move to the closed configuration (FIG.54).

FIGS. 50 to 54 illustrate the reflux device 200 positioned at adysfunctional LES 300 that does not close completely, and passage of afood bolus 305 through the reflux device 200 at the dysfunctional LES300.

LES muscle 300 is dysfunctional and does not close normally—device 200in anti-reflux configuration (FIG. 50).

Patient chews and swallows bolus of food 305 (FIG. 51).

Bolus 305 is propelled through the oesophagus 202 via peristalsis and ispushed through the anti-reflux barrier 203, which deforms readily (FIG.52). Device anti-reflux barrier 203 relaxes gradually so as to assumeanti-reflux configuration (FIG. 53).

Food bolus 305 has passed and device 200 maintains anti-refluxprotection (FIG. 54).

The device 200 is also suitable for use in the case where theoesophageal sphincter opens erratically, or for relatively long periodsof time, e.g. greater than 10 seconds, or when there is no food passingthrough the oesophagus 202 into the stomach 201, as illustrated in FIGS.59 to 60. When the oesophageal sphincter opens (FIGS. 55 and 56), thevalve leaflets 206 expand gradually and thus the valve member 203gradually closes (FIG. 57). The valve member 203 remains in this closedconfiguration preventing reflux from the stomach 201 into the oesophagus202, until the oesophageal sphincter begins to close again (FIG. 59).When the oesophageal sphincter closes fully, the valve leaflets 206 arecontracted (FIG. 60). However reflux from the stomach 201 to theoesophagus 202 is still prevented.

FIGS. 55 to 60 illustrate the reflux device 200 positioned at thefunctioning LES 300 during opening/closing of the muscle.

LES muscle 300 open (either normally or inappropriately)—device 200 inanti-reflux configuration (FIG. 58).

LES 300 begins to close normally—device anti-reflux barrier 203 beginsto compress (FIG. 59).

LES 300 closed—device anti-reflux barrier 203 completely collapsed toallow muscle closure (FIG. 60).

LES 300 begins to open—anti-reflux barrier 203 stays compressed (FIG.55).

LES 300 open—anti-reflux barrier 203 stays compressed (FIG. 56).

LES 300 open for abnormally prolonged period of time—anti-reflux barrier203 relaxes gradually so as to assume anti-reflux configuration (FIG.57).

When the device 200 has been deployed in the oesophagus 202 and/orstomach 201, the therapeutic agent 209 may be delivered from the cellstruts 210 in the lining member 204 to the inner surface of theoesophagus 202/stomach 201.

It will be appreciated that there are a variety of possibleconfigurations for the valve member 203 and for the lining member 204.FIGS. 61 to 74 illustrate a variety of possible configurations for thevalve member 203 and for the lining member 204.

FIGS. 61 to 74 illustrate a variety of different possible anti-refluxbarrier geometrical designs. In FIG. 73 the distal side of the valveleaflet 206 is nicked. In FIG. 74 the valve member 203 is sliced.

In FIGS. 75 to 78 there is illustrated another medical treatment device220 according to the invention, which is similar to the device 200 ofFIGS. 26 to 60, and similar elements in FIGS. 75 to 78 are assigned thesame reference numerals.

In this case the support member 205 extends proximally of the proximalend of the lining member 204.

FIGS. 79 to 82 illustrate a further medical treatment device 225according to the invention, which is similar to the device 200 of FIGS.26 to 60, and similar elements of FIGS. 79 to 82 are assigned the samereference numerals.

In this case the proximal region of the lining member 204 has asubstantially zig-zag, wave pattern aligned with the proximal supportelement 207.

Referring to FIGS. 83 to 86 there is illustrated another medicaltreatment device 230 according to the invention, which is similar to thedevice 225 of FIGS. 79 to 82, and similar elements in FIGS. 83 to 86 areassigned the same reference numerals.

In this case the radial dimension of the support member 205 issubstantially constant along the support member 205.

In FIGS. 87 to 90 there is illustrated another medical treatment device235 according to the invention, which is similar to the device 230 ofFIGS. 83 to 86, and similar elements in FIGS. 87 to 90 are assigned thesame reference numerals.

In this case the device 235 comprises a proximal support member 236 anda distal support member 237. The two support members 236, 237 aresubstantially equal in size. The proximal support member 236 is locatedproximally of the valve member 203 and the distal support member 237 islocated distally of the valve member 203.

FIGS. 91 to 94 illustrate a further medical treatment device 240according to the invention, which is similar to the device 235 of FIGS.87 to 90, and similar elements in FIGS. 91 to 94 are assigned the samereference numerals.

In this case the distal support member 237 is smaller in size than theproximal support member 236. In particular the radial dimension of thedistal support member 237 is smaller than the radial dimension of theproximal support member 236.

Referring to FIGS. 95 to 98 there is illustrated another medicaltreatment device 245 according to the invention, which is similar to thedevice 200 of FIGS. 26 to 60, and similar elements in FIGS. 95 to 98 areassigned the same reference numerals.

In this case the support member 205 tapers distally radially outwardly.The support member 205 is arranged extending co-axially around the valvemember 203.

FIGS. 75 to 98 illustrate a variety of different retention mechanismdesigns.

In FIGS. 99 to 103 there is illustrated a support member 250 of anothermedical treatment device according to the invention, which is similar tothe device 200 of FIGS. 26 to 60, and similar elements in FIGS. 99 to103 are assigned the same reference numerals.

In this case each support element 207 comprises two articulation regions251 intermediate each coupling region 208 and the adjacent couplingregion 208.

FIGS. 99 to 103 illustrate the retention mechanism with multiplearticulation sites. FIG. 102 illustrates the first articulation site.FIG. 101 illustrates the second articulation site.

FIGS. 104 to 110 illustrate a support member 255 of a further medicaltreatment device according to the invention, which is similar to thedevice of FIGS. 99 to 103, and similar elements in FIGS. 104 to 110 areassigned the same reference numerals.

In this case each support element 207 comprises three articulationregions 256 intermediate each coupling region 208 and the adjacentcoupling region 208.

FIGS. 104 to 110 illustrate the retention mechanism with multiplearticulation sites. FIG. 106 illustrates the first articulation site.FIG. 107 illustrates the second articulation site. FIG. 109 illustratesthe third articulation site.

FIGS. 27 to 30 and 99 to 110 illustrate features of the retentionmechanism and desirable geometries.

Referring to FIGS. 1 to 25, there are illustrated various other medicaldevices according to the invention. In general the medical device may bea sleeve or prosthesis, as illustrated in one basic form in FIG. 6.

FIG. 1 is an illustration of a medical device loaded onto a deliverydevice. FIGS. 2 and 3 are cut away illustrations of the medical deviceat a deployment site. FIGS. 4 and 5 are close up illustrations of themedical device and deployment action.

The medical device of the invention may have various forms. Other thanthe form illustrated in FIG. 6, the medical device may take the formshown in FIGS. 18 to 25 for example, which is that of an elastic/viscoelastic material twisted into form to provide a valving mechanism.

The medical device of the invention may be deployed by means of aballoon catheter, as illustrated in FIGS. 7 to 10. The medical devicemay be deployed by means of a tube which may have shoulders to alleviatedeployment, as FIGS. 13 and 14 illustrate.

The medical device may be retained in position by any of a number ofpossible mechanisms, such as adhesive (FIGS. 17(a) and 17(b)), rings(FIGS. 11 to 14), barbs (FIGS. 15 to 17), bullet form (FIGS. 17(d) to17(f)).

Various embodiments of the medical device according to the invention aredescribed in further detail as follows.

Referring to FIGS. 1 to 5 there is illustrated a medical kit 1 accordingto the invention comprising a medical device 2 and a delivery device 3.Together the medical device 2 and the delivery device 3 may be employedto treat a part of an inner surface of an alimentary canal, such as partof the inner surface of the oesophagus 4. The delivery device 3 issuitable for delivering the medical device 2 to a desired deploymentlocation in the oesophagus 4.

The medical device 2 comprises a tubular sleeve 5 for lining part of theinner surface of the oesophagus 4. The sleeve 5 defines a lumen 6through the sleeve 5. As illustrated in FIG. 5, the sleeve 5 may beemployed to line around the entire circumference of part of the innersurface of the oesophagus 4.

The sleeve 5 has a contracted delivery configuration (FIG. 3) fordelivery of the sleeve 5 through the oesophagus 4 to the desireddeployment location, and an expanded deployment configuration (FIG. 4)for deployment at the desired deployment location in the oesophagus 4.

The sleeve 5 is of a polymeric material, in this case. The material ofthe sleeve 5 may be bioabsorbable and/or biodegradable.

The sleeve 5 may be loaded with a pharmaceutical agent to facilitatedelivery of the pharmaceutical agent to the inner surface of theoesophagus 4.

The delivery device 3 comprises an expandable portion 7, in this case inthe form of a balloon element, mounted to the distal end of an endoscope8. The medical device 2 may be mounted over the balloon element 7. Theballoon element 7 has a contracted delivery configuration (FIG. 3) fordelivery of the medical device 2 through the oesophagus 4 to the desireddeployment location in the oesophagus 4, and an expanded deploymentconfiguration (FIG. 4) for deployment of the medical device 2 at thedesired deployment location in the oesophagus 4.

In use, the sleeve 5 in the contracted delivery configuration is mountedaround the balloon element 7 in the contracted delivery configuration.The delivery device 3 is then inserted through the patient's mouth andadvanced through the oesophagus 4 until the sleeve 5 is located adjacentto the desired deployment location in the oesophagus 4 (FIG. 3).

The balloon element 7 is inflated to move the balloon element 7 from thecontracted delivery configuration to the expanded deploymentconfiguration, and thus move the sleeve 5 from the contracted deliveryconfiguration to the expanded deployment configuration to deploy thesleeve 5 at the desired deployment location to line part of the innersurface of the oesophagus 4 (FIG. 4). In this manner, the oesophagus 4may be treated. The balloon element 7 may then be deflated to move theballoon element 7 from the expanded deployment configuration to thecontracted delivery configuration. During deflation, the sleeve 5remains in the expanded deployment configuration, as illustrated in FIG.5. The delivery device 3 with the balloon element 7 in the contracteddelivery configuration is withdrawn from the oesophagus 4 (FIG. 5).

In this embodiment, the invention comprises:

-   -   1. The device 7, which connects to the end of the endoscope 8.        The device 7 has an expandable component (delivery system),        which, when expanded can apply a symmetrical radial pressure to        the endothelium 4 of the gastric lumen within the        gastrointestinal (GI) tract. Such a component could be an        inflatable balloon or a mechanically expandable device, as shown        in FIGS. 1 to 5.    -   2. The soft polymeric sleeve 5 (therapeutic component) that is        loaded onto the outside of the expandable component 7. The soft        polymeric sleeve 5 can be expandable and elastic, but may        alternatively exhibit plastic deformation so that once expanded        it retains its shape. The polymeric sleeve 5 may be inherently        elastic but might be held in its expanded position by a        plastically deformable support material. The polymeric sleeve 5        could additionally have a bio-adhesive outer surface.

The device comprising the delivery system 7 and the therapeuticcomponent 5 can be attached to the end of the endoscope 8. A cliniciancan introduce the device into the gastric lumen and position it close toa wound or lesion 100. By expanding the delivery device 7, thetherapeutic component 5 can be pressed against the gastric endothelium4. The therapeutic component 5 can be retained at the site using eitherbio-adhesive or mechanical means or a combination of these.

FIG. 1 illustrates the endoscope 8 with the balloon 7. FIG. 2illustrates the oesophageal lesion 100. FIG. 3 illustrates insertion ofthe polymeric sleeve 5 into the oesophageal lumen. FIG. 4 illustratesballoon inflation within the lumen. FIG. 5 illustrates sleeve adhesion.

In FIG. 6 there is illustrated another medical device 10 according tothe invention, which is similar to the medical device 2 of FIGS. 1 to 5,and similar elements in FIG. 6 are assigned the same reference numerals.

The medical device 10 is suitable for being deployed in a curved ortortuous section 11 of the alimentary canal, as illustrated in FIG. 6,to line part of the inner surface of the alimentary canal.

FIG. 6 illustrates the tubular sleeve 5 conforming to a tortuous part ofthe gastrointestinal tract.

FIG. 6 illustrates the polymeric sleeve 5 implanted in a tortuouslocation.

Unlike a relatively rigid metal stent system, the polymeric sleeve 5 ofthe invention can conform to the tortuosity and irregularities of the GItract, as illustrated in FIG. 6. This is important to optimiseinterfacial contact between the gastric endothelium 11 and the surfaceof the sleeve 5. Such a system can facilitate wound healing; woundprotection and drug delivery profiles not achievable using alternativesystems.

In addition polymeric sleeves can be designed to degrade over apre-defined period of time, which is not possible with a metallic stent,which may have to be left in place.

Multiple polymeric sleeves can be loaded onto a single delivery deviceand can be overlapped in-situ without any of the problems associatedwith doing this using stents, such as reduction in endoluminal diameter,doubling of drug delivery dose at overlap points.

FIGS. 7 to 10 illustrate another medical kit 20 according to theinvention, which is similar to the medical kit 1 of FIGS. 1 to 5, andsimilar elements in FIGS. 7 to 10 are assigned the same referencenumerals.

The sleeve 5 may have a pre-defined elasticity and lumen size, asillustrated in FIGS. 7 to 10.

FIGS. 7 to 10 illustrates insertion of the device into the oesophagus 4and inflation of the device followed by withdrawal of the balloonelement 7.

In FIGS. 10(a) to 10(h) there is illustrated another medical device 80according to the invention, which is similar to the medical device 2 ofFIGS. 1 to 5, and similar elements in FIGS. 10(a) to 10(h) are assignedthe same reference numerals.

In this case the sleeve 5 is of a viscoelastic foam, and is selfexpandable upon elapse of a predetermined period of time, for example 7to 10 seconds, from a contracted deployment configuration (FIG. 10(e))to an expanded deployment configuration (FIG. 10(g)) to seal the lumen 6through the sleeve 5. The sleeve 5 is contractable from the expandeddeployment configuration (FIG. 10(g)) to the contracted deploymentconfiguration (FIG. 10(h)) by the compression force exerted by the wallsof the oesophagus 4. The sleeve 5 is biased towards the expandeddeployment configuration.

The medical device 80 is particularly suitable for use with anoesophagus experiencing transient lower oesophageal sphincterrelaxation.

Erosion of an oesophagus by acid reflux may be mediated through a numberof mechanisms. The relaxation of the lower oesophageal sphincter (LOS)is one cause of reflux. Relaxation of the LOS occurs normally during theswallowing process but may also occur transiently and randomly for noapparent reason, which is known as lower oesophageal relaxation (TLOSR).In some pathological conditions the LOS may be chronically relaxed.Hiatus hernia may result in incomplete LOS muscle contraction duringwhich time reflux may be triggered by straining.

Upon swallowing, the walls of the oesophagus 4 expand to open the LOS 81(FIG. 10(b)), to facilitate food or the like to pass through the LOS 81into the stomach 82 (FIG. 10(c)). In the event where the LOS 81 closesnormally, the sleeve 5 remains in the contracted deploymentconfiguration throughout the swallowing process. As the sleeve 5 expandsto the expanded deployment configuration only after elapse of 7 to 10seconds, there is not sufficient time during the normal swallowingprocess for the sleeve 5 to expand. Upon closing of the LOS 81 thesleeve 5 in the contracted deployment configuration seals across theoesophagus 4 (FIG. 10(d)).

In the event of TLOSR, where the LOS 81 does not close normally after 7to 10 seconds, the sleeve 5 expands to the expanded deploymentconfiguration to seal across the oesophagus 4 to prevent acid refluxfrom the stomach 82 (FIG. 10(g)). Upon the eventual closure of the LOS81, for example after elapse of 120 seconds, the sleeve 5 is compressedby the action of the walls of the oesophagus 4 to the contracteddeployment configuration (FIG. 10(h)).

FIGS. 10(a) to 10(h) illustrates the sleeve shaped device 80 made fromviscoelastic foam. The device 5, once secured, will expand to fill anyopening in the LOS 81. In the event of closing of the LOS 81, the device5 will compress significantly allowing the LOS 81 to function normallyas illustrated by FIG. 10(d). The action of swallowing will open the LOS81 and the lumen of the device 5 (FIGS. 10(b) and 10(c)) but the device5 will not expand unless the LOS 81 is open for a prolonged period oftime. If the LOS 81 opens transiently (TLOSR) for longer than 10 seconds(FIG. 10(e)), the device 5 will expand thus closing the open oesophageallumen (FIG. 10(g)).

The medical device 80 addresses the problem of TLOSRs specifically anddoes not result in impaired normal swallowing. The expansion functionsonly during TLOSRs but remains inactive during normal swallowing inducedmuscle relaxation. Considering that normal swallowing causes a 4 to 7second relaxation of the LOS 81, whereas TLOSR causes a relaxation of upto 120 seconds, the medical device 80 has a time-dependant mode ofaction.

FIG. 10(i) illustrates another medical device 120 according to theinvention, which is similar to the medical device 2 of FIGS. 1 to 5, andsimilar elements in FIG. 10(i) are assigned the same reference numerals.

In this case the radial dimension of the outer surface of the sleeve 5varies along the sleeve 5 and the radial dimension of the inner surfaceof the sleeve 5 varies along the sleeve 5. In particular the outersurface of the sleeve 5 tapers inwardly from each end towards the centreof the sleeve 5, and the inner surface of the sleeve 5 tapers inwardlyfrom each end towards the centre of the sleeve 5.

The device 120 may take the form of the elastic material as shown inFIG. 10(i). The elastic material by its nature creates a valve byclosing in the centre thus pulling the tissue, that the sleeve 5 islining, inwardly.

Referring to FIG. 10(j) there is illustrated another medical device 130according to the invention, which is similar to the medical device 120of FIG. 10(i), and similar elements in FIG. 10(j) are assigned the samereference numerals.

In this case the radial dimension of the outer surface of the sleeve 5is substantially constant along the sleeve 5.

The device 130 may be of a foam so that it forms a valve in thegastrointestinal tract. The foam may be designed to allow materials topass into the stomach by means of peristaltic action.

Referring to FIG. 11 there is illustrated another medical device 30according to the invention, which is similar to the medical device 2 ofFIGS. 1 to 5, and similar elements in FIG. 11 are assigned the samereference numerals.

In this case the medical device 30 comprises a first support ring 31 ata first end of the sleeve 5 and a second support ring 32 at a second endof the sleeve 5 spaced-apart from the first support ring 31. Togetherthe support rings 31, 32 acts as support elements to support the sleeve5 in the expanded deployment configuration lining part of the innersurface of the oesophagus 4.

The support rings 31, 32 may be coupled to the sleeve 5 in any suitablemanner. For example the support rings 31, 32 may be embedded within thesleeve 5. Alternatively the support rings 31, 32 may be providedexternally of the sleeve 5, and the support rings 31, 32 may beconfigured to engage the inner surface of the sleeve 5.

The polymeric sleeve 5 may have one or more supporting rings 31, 32 toensure a tight fit to the lumen of the GI tract, as shown in FIG. 11.The rings 31, 32 may be expandable or rigid and may be attached to thesleeve 5 or may be positioned separately. The expandable rings 31, 32may be made from elastically or plastically deformable material.

The sleeve 5 may have rings with different sizes to enable fitting toirregularly shaped spaces.

Alternatively small elastic rings may be placed in the centre of thesleeve 5 to form a “sphincter” like structure.

FIG. 11 illustrates the elastomeric/hydrogel material 5 and thesupporting rings 31, 32 of varying width.

FIG. 11 illustrates the polymeric sleeve 5 with the supporting rings 31,32 of similar size.

In FIG. 12 there is illustrated a further medical device 40 according tothe invention, which is similar to the medical device 30 of FIG. 11, andsimilar elements in FIG. 12 are assigned the same reference numerals.

In this case the medical device 40 comprises a third support ring 41intermediate the first support ring 31 and the second support ring 32.

The sleeve 5 is substantially frusto-conically shaped, having a smallerdiameter adjacent to the first support ring 31 than adjacent to thesecond support ring 32.

FIG. 12 illustrates the numerous supporting rings 31, 32, 41 and thesoft conforming elastomeric/hydrogel 5.

FIG. 12 illustrates the polymeric sleeve 5 with the supporting rings 31,32, 41 of varying size.

FIGS. 13 and 14 illustrate another medical kit 50 according to theinvention, in which the medical device is similar to the medical device30 of FIG. 11 and the delivery device is similar to the delivery device3 of FIGS. 1 to 5, and similar elements in FIGS. 13 and 14 are assignedthe same reference numerals.

In this case the medical device 53 comprises a plurality of supportrings 51 between the first support ring 31 and the second support ring32. The support rings 51 are spaced-apart along the sleeve 5.

The medical device 53 has a shortened delivery configuration in whichthe support rings 31, 32, 51 are closely adjacent one another, and anelongated deployment configuration in which the support rings 31, 32, 51are spaced-apart from one another.

The delivery device 54 comprises the endoscope 8 and an ejector housedwithin the endoscope 8. In the delivery configuration the ejector isspaced proximally of a distal end of the endoscope 8 to create areception space 52 at the distal end of the endoscope 8 for receivingthe medical device 53 for delivery of the medical device 53 through theoesophagus 4 to the desired deployment location.

The endoscope 8 has an outlet 55 at the distal end of the receptionspace 52. A radially outwardly protruding shoulder 56 is providedextending around the circumference of the outlet 55.

The ejector is movable distally relative to the endoscope 8 from thedelivery configuration to the deployment configuration to pass themedical device 53 out of the reception space 52 through the outlet 55 todeploy the medical device 53 at the desired deployment location in theoesophagus 4.

In use, the medical device 53 is arranged in the shortened deliveryconfiguration with the support rings 31, 32, 51 closely adjacent oneanother and loaded into the reception space 52 of the endoscope 8. Thedelivery device 54 is then inserted through the patient's mouth andadvanced through the oesophagus 4 until the outlet 55 is adjacent to thedesired deployment location in the oesophagus 4.

To deploy the medical device 53 out of the reception space 52, theejector is maintained in a fixed position and the endoscope 8 iswithdrawn proximally, thus causing the medical device 53 to pass out ofthe reception space 52 through the outlet 55 (FIG. 14). As the medicaldevice 53 is deployed the support rings 31, 32, 51 move apart from oneanother and thus the medical device 53 is deployed in the oesophagus 4in the elongated deployment configuration to line the inner surface ofthe oesophagus 4. In this manner the oesophagus 4 may be treated. Whenthe medical device 53 has been fully deployed, the delivery device 54 iswithdrawn from the oesophagus 4.

The polymeric sleeve 5 is loaded into a dispensing tube that fits ontothe end of the endoscope 8. Contained within the dispensing tube is theexpandable polymeric sleeve 5 that may be ribbed or segmented, and therequired length can be dispensed and detached from the dispenser 52, asshown in FIG. 13. The dispenser has a raised edge 56 that allows theoesophageal tissue 4 to be lifted out of the way during use, as shown inFIG. 14.

FIG. 13 illustrates the segment detachment point 55.

FIG. 13 illustrates the device for dispensing segmented polymericsleeves 5 from the end of the endoscope 8.

FIG. 14 illustrates the device dispensing a segmented polymeric sleeve 5into the gastric lumen

Referring to FIGS. 15 to 17 there is illustrated another medical device60 according to the invention, which is similar to the medical device 2of FIGS. 1 to 5, and similar elements in FIGS. 15 to 17 are assigned thesame reference numerals.

In this case the medical device 2 comprises a plurality of anchorelements 61 extending through the sleeve 5. Upon inflation of theballoon element 7, the anchor elements 61 are extendable into the wallof the oesophagus 4 to engage the oesophagus wall, and thereby anchorthe sleeve 5 to the oesophagus wall. In this manner the sleeve 5 issupported in the expanded deployment configuration lining part of theinner surface of the oesophagus 4.

The exterior of the sleeve 5 could have an adhesive layer or securingmechanism (FIGS. 15 to 17), which, when expanded using the balloon 7 inthe oesophagus 4 adheres to the oesophageal endothelium. Uponrelaxation, the sleeve 5 will pull the sphincter closed.

This device could be used to improve the effectiveness of theoesophageal sphincter and could be adjusted on demand by the surgeon.

FIGS. 15 to 17 illustrates a securement mechanism in use, where clips 61are pushed through the wall of the oesophagus 4 by device expansion,such as balloon inflation.

It will be appreciated that a range of means may be employed to supportthe sleeve 5 lining part of the inner surface of the oesophagus 4. Forexample, the sleeve 5 may be attached to the inner surface of theoesophagus 4, such as by means of an adhesive 90, as illustrated inFIGS. 17(a) and 17(b).

Referring to FIGS. 17(d) to 17(f) there is illustrated another medicaldevice 110 according to the invention, which is similar to the medicaldevice 60 of FIGS. 15 to 17, and similar elements in FIGS. 17(d) to17(f) are assigned the same reference numerals.

In this case the medical device 110 comprises four anchor elements 111mounted to the exterior surface of the sleeve 5. Each anchor element 111is conically shaped with a pointed tip 112 to form a substantiallybullet shaped retainer element. The anchor elements 111 are extendableinto the wall of the oesophagus 4 to engage the oesophagus wall, andthereby anchor the sleeve 5 to the oesophagus wall. In this manner thesleeve 5 is supported in the expanded deployment configuration liningpart of the inner surface of the oesophagus 4 (FIG. 17(f)).

In FIGS. 18 to 25 there is illustrated a further medical device 70according to the invention, which is similar to the medical device 2 ofFIGS. 1 to 5, and similar elements in FIGS. 18 to 25 are assigned thesame reference numerals.

In this case the sleeve 5 is twistable to move the sleeve 5 between anopen configuration (FIGS. 18 and 22) in which the lumen 6 is open, and asealed configuration (FIGS. 21 and 25) in which the lumen 6 is closed.

The implantable sleeve 5 described above could have an “hourglass”shape, as illustrated in FIGS. 18 to 21. This shape would enable thedevice to be located and secured at the oesophageal sphincter. Inaddition the device can be twisted in-situ by the clinician to tailorthe elasticity of the orifice created. The sleeve 5 could be held inplace either by sutures or by an adhesive.

FIGS. 18 to 21 illustrate the sleeve 5 designed as a sphincter implantwith adjustable opening tightness.

In another embodiment of the invention, the delivery device comprises acover element slidably mounted to the endoscope 8. The cover element ismovable relative to the endoscope 8 between a delivery configuration inwhich the medical device is restrained beneath the cover element, and adeployment configuration in which the cover element is retracted touncover the medical device and thus facilitate deployment of the medicaldevice.

The invention has been described above with reference to FIGS. 1 to 25in relation to treatment of the inner surface of an oesophagus. Howeverit will be appreciated that the invention may be employed to treat theinner surface of other parts of the alimentary canal, such as the innersurface of the stomach or the inner surface of the colon. In such casesthe medical device may be configured to line part of the inner surfaceof the stomach or part of the inner surface of the colon, and thedelivery device may be configured to deliver the medical device to adeployment location in a stomach or in a colon.

It will be appreciated that the medical device may be configured to linearound only part of the circumference of part of the inner surface ofthe alimentary canal. In this case the medical device may be provided inthe form of a patch or a prosthesis.

Alternative Applications

An application other than erosive gastric disease that would benefitfrom the invention is gastric cancer. Current treatment involvessaturating the gastric tissue with highly toxic chemotherapeutic agents,which give rise to unpleasant side effects. Facilitating thelocalisation or targeting of such drugs to a specific site willsignificantly reduce the dosage required and improve the therapeuticefficacy. Specifically, cancers of the oesophagus, colon and biliarytree could be treated using this approach.

Other indications that could be targeted with this therapeutic approachare wound healing of caustic burns, radiotherapy induced lesions orpost-surgical trauma. The invention may be useful in the prevention ofstricture and anastamotic leakage.

The invention may be employed for localised and prolonged treatment ofulcerative colitis, eosinophilic colitis and inflammatory bowel disease.

The invention is not limited to the embodiments hereinbefore described,with reference to the accompanying drawings, which may be varied inconstruction and detail.

1. A medical device suitable for treating reflux from a stomach to anoesophagus, the device comprising: a valve member; the valve memberbeing movable between an open configuration to facilitate passage ofmaterial between an oesophagus and a stomach, and a closedconfiguration; the valve member being configured to gradually move fromthe open configuration to the closed configuration over a predeterminedperiod of time.